“When I first read the script I laughed a lot, and that’s always a good sign,” says Butterfield, 21. “It was very well-written [and it was] very aware of what it was trying to do and be. I just found all the characters incredibly charming and endearing and believable and complex.

“ I don’t think you get that very often— especially in comedies.”

“Sex Education” follows an awkward teen boy (Butterfield), whose single mother (Anderson) is a sex therapist. He’s often embarrassed by her, but he’s also absorbed some of her teachings. When he helps a classmate with a sexual problem, a fellow student persuades him to launch an underground sex therapy clinic at his high school.

The show is filled with homages to John Hughes and ’90s teen classics such as “10 Things I Hate About You” as well as a sharper British sensibility in the vein of “Skins.”

The London-born Butterfield began his career as a child actor in films such as “Ender’s Game” and “Miss Peregrine’s Home for Peculiar Children.” For him, this show was a chance to do something new.

“This was my first recurring TV role,” he says. “Film is a bit more concise. There’s a lot more to keep track of [in TV] which wasn’t incredibly difficult but it was just something I hadn’t done before in such depth.”

In order to research the role, Butterfield was able to consult an unlikely source in a life-imitating-art-type twist: his mother.

“Gillian was lovely, we got on really well,” he says. “It felt very real and at times very similar to my experience with my mom— she’s a psychologist. There are a lot of similarities in that regard.”

While Butterfield says Anderson’s character is more overbearing than his own mother, “I did speak with [my mom] about what it means to be a therapist and the responsibility, which is quite interesting and something I didn’t really appreciate until I was in that position myself, in character.”

“Sex Education” was also educational behind the scenes. The Wales-based set was brimming with real books about sex.

“In the house — the set where my character lives — there’s hundreds of books about sex, and posters and pamphlets,” says Butterfield. “So [there was] a lot to be learned just from wandering around the set!”

Butterfield says that while the show is funny, he also hopes it has a positive impact.

“You don’t feel it at the time but when you’re growing up more you’re like, ‘Wow, there’s a lot of stuff [about sex] they didn’t teach you,’ ” he says. “There’s a lot that people learn from talking to their friends or from social media, which really isn’t the place you want to be getting your perspective of things like sex.

“I think it’s important for us to be able to create a show which was able to show [sex] in a very frank and honest and real way, and it didn’t glorify or glamorize it.”